In less than an hour, Cantin was dead, shot by one of his own men. Rebels were lobbing grenades at the platoon as soldiers struggled to carry his body and three wounded comrades through the dense growth. Panicked, the GIs rolled a man with a chest wound onto his stomach, killing him.

"It didn't go well," platoon leader Cantin, a native of Manchester, N.H., said after their first day of jungle training earlier this month. But he was confident that the three-week course would turn his men into a top-notch team for jungle combat.

Cantin and his platoon and others in the 3rd Battalion, 502nd Regiment, 101st Airborne Division, based at Ft. Campbell, Ky., wrap up their course here today, the last such U.S. Army unit to have the chance to hone jungle skills.

On Thursday, the 45-year-old Jungle Operations Training Battalion in Panama, one of the Army's premier training centers, will close. There are no plans to replace it.

The center is a victim of a 2-decade-old international treaty, Defense Department cutbacks, pressure to arm the military with high-tech equipment and a belief that jungle wars for the U.S. are in the past.

Still, there are worries that along with the center will go the opportunity to learn technical skills, taught in few other places, that better prepare U.S. fighting forces for battle or peacekeeping missions, whether in the desert, mountains or jungle.

"It can't be replicated in the States," said Cantin, who completed the program as a staff sergeant seven years ago.

In another corner of the 23,000-acre training site, Staff Sgt. Randall Moody and his men were learning to capsize and right a rubber raft called a Zodiac, practicing a skill needed if the craft becomes waterlogged. With nine years in the Army, Moody, a native of Jacksonville, Fla., had never paddled a Zodiac before.

In the final week of training, soldiers go into a "village" where they must convince egg-throwing townspeople to show them caches of guerrilla weapons. Panamanians who play the villagers speak only Spanish. Then the soldiers confront a sniper, and afterward a television crew.

Every battalion to come through the training center over the past two years has requested that exercise.

"Units have come here and then gone to Bosnia," said Maj. Dan Gettings, second-in-command at Ft. Sherman. "This has made American soldiers better prepared to deal with an uncertain situation. There is [nothing] much more uncertain than a peacekeeping mission."

However, a 1977 treaty signed by President Carter and Gen. Omar Torrijos called on the U.S. to turn over the canal to Panama by 2000 and to close all U.S. bases here.

With an annual combined budget of $4 million for training nearly 9,000 soldiers a year, Ft. Sherman and the jungle program are considered an efficient operation. But starting another center is a different matter.

"The initial infrastructure costs would be considerable," Gettings said. With the $260-billion defense budget proposed for 2000 nearly $3 billion less than this year's expected spending and pressures to buy expensive, high-tech equipment, the Army is looking for ways to save money, not spend it.

From now on, U.S. soldiers will receive jungle training only as small units through exchange programs with other countries. No such agreements have been negotiated, said Raul Duany, spokesman at U.S. Southern Command.

Jungle operations switched from individual to battalion-level training in 1976 to build fighting units that were prepared for jungle warfare, said Sgt. 1st Class David Stewart. A typical infantry battalion numbers from 500 to 900 soldiers.

"We can test all the systems that a battalion has--logistics, support, medicine--and get them training in a jungle environment," he said.

Still, the U.S. armed forces are not putting a premium on jungle skills these days. "We always focus on the last war, and that is desert warfare," said Gettings, an amateur historian, referring to the 1991 Persian Gulf conflict.

Nonetheless, all of the information developed here in nearly half a century of training jungle fighters is being recorded on computer disks. Former instructors are being invited to add their observations and experiences.

"The information is not going away," Stewart said, "just the environment."